First I needed a hole in the side. I didn't take pictures. I read different ways to do it but didn't have a diamond drill and didn't want to wait. I broke out my dremel tool and a grinding tip. I stabilized the bottle in a crate with material around it on its side. Since I didn't want it shattering I taped the area with masking tape. I started grinding. It wasn't as hard as I expected.
After reading several how to ideas I jumped in. I used a long string 100 lights since it was a gallon bottle.
Cut the plug off where you can re-wire taping well.
I then used a twisty to keep some from settling to the bottom.